As illustrated in FIG. 1, a radio frame transmitted between a User Equipment and a base station in a mobile communication system of Long Term Evolution Type 2 wideband Time Division Duplex (LTE Type 2 TDD) has a length of 10 ms. Each radio frame is divided into two half-frames. Each half-frame includes seven sub-frames (also referred to as data timeslots) and three special timeslots. In an LTE system with a bandwidth of 20 MHz, for example, the bandwidth of the system is 20 MHz, an interval between sub-carriers is Δf=15 KHz, the number of FFT sample points is NFFT=2048, and the minimum time unit Ts=1/(Δf×NFFT)=1/(15000×2048)=0.03255 μs. In this case, each of the seven data timeslots is used for transmission of uplink or downlink data and is consisted of Cyclic Prefixes (CPs) and Orthogonal Frequency Division Multiplex (OFDM) symbols, where each OFDM symbol has a length of 2048×Ts, each short CP has a length of 256×Ts, each long CP has a length of 544×Ts, and each data timeslot has a total length of 675 μs (20736×Ts). The data timeslots may be divided into uplink timeslots and downlink timeslots; each downlink timeslot includes nine OFDM symbols in the case of short CPs, or eight OFDM symbols in the case of long CPs, and each uplink timeslot includes nine long blocks in the case of short CPs, or eight long blocks in the case of long CPs. The seven data timeslots may be identified with #0, #1, #2, #3, #4, #5 and #6 or with TS0, TS1, TS2, TS3, TS4, TS5 and TS6, where #0 corresponds to TS0, #1 corresponds to TS1, and the like. Timeslot #0 is used only for downlink. The three special timeslots include a downlink special timeslot (DwPTS), a guard timeslot (GP) and an uplink special timeslot (UpPTS), where the downlink special timeslot DwPTS with a length of 2572×Ts is located succeeding the timeslot TS0 and includes one CP (with a length of 524×Ts) and one OFDM symbol (with a length of 2048×Ts), which is used for carrying a primary synchronous channel (P-SCH) to implement operations such as searching for a cell and downlink synchronization, while a secondary synchronous channel (S-SCH) is transmitted in the last symbol of the data timeslot #0; the uplink special timeslot UpPTS with a length of 4340×Ts is located succeeding the GP and preceding the timeslot TS1 to enable an uplink random access, etc; and the guard timeslot GP with a length of 50 μs (1536×Ts), which carries no data signal, is located preceding the uplink special timeslot UpPTS to prevent interference of the downlink special timeslot with the uplink special timeslot.
In the foregoing data frame structure, occupancy of the last symbol of the timeslot #0 by the S-SCH limits the efficiency of transmitting information such as a broadcast channel (BCH) in the timeslot #0. On the other hand, since the DwPTS is spaced from the uplink timeslot by a timeslot GP only, when the DwPTS is drifting or the power of the DwPTS is increased, interference of the DwPTS with the uplink timeslot may be caused, resulting in a degraded communication quality.